Conventionally, a known toilet seat device can measure the body weight of a user by utilizing a toilet seat provided in an upper part of a sit-down flush toilet. Compared to a general body weight scale, the toilet seat device that can measure the body weight does not need storage space or the effort of obtaining the scale from the storage location and replacing it after each measurement is performed. Further, the sit-down flush toilet can perform daily body weight management continuously without conscious effort because the sit-down flush toilet is likely to be used daily by the user.
It is favorable to provide a load sensor at a support leg part of the toilet seat to be able to measure the body weight using a toilet seat device having a simple configuration (e.g., JP-A H6-8548 (Tokko)). To accurately measure the body weight of the user using the load sensor provided at the support leg part of the toilet seat, it is necessary for the total body weight of the user to be applied to the support leg part of the toilet seat. However, for the toilet seat device, for example, a foot of the user may undesirably touch the floor of the toilet room and cause the body weight of the user to be undesirably dispersed in the floor via the foot; therefore, the total body weight of the user is no longer applied to the toilet seat. Also, because the toilet seat is pivotally supported to be rotatable with respect to the main part, the body weight of the user may be dispersed through the rotation shaft part; and the total body weight of the user is no longer applied to the support leg part of the toilet seat.
Therefore, a toilet seat device is known in which the weight corresponding to the body weight applied to parts other than the toilet seat is predetermined by experiments, etc., before the body weight measurement; and the seated load that is measured by the toilet seat is increased by the weight corresponding to the body weight (e.g., JP-A H9-119859 (Kokai)).
However, the inventor of the application discovered that the body weight of the user dispersed in the floor of the toilet room and/or the rotation shaft part of the toilet seat changes greatly according to the physique, the sitting habits, etc., of the user; therefore, it is difficult to use the values determined by the experiments, etc., uniformly for all users.